What difficulties does fog create for Londoners?

Over-saturation of moisture in the air becomes the cause of the formation of fog. Usually fogs are formed in places with high humidity such as swamps, rivers, lakes. But cities are no exception. Fogs in London are yellow. This is due to the large number of fireplaces that burn coal. From this comes a huge release of soot and smoke into the atmosphere. These fogs are dangerous, firstly for people from lung and heart diseases, and the permeability of the sun’s rays is reduced, which leads to a lack of vitamin D.